Searching databases for particular information is a central task of modern data processing. The larger the database, the greater the need for solutions which output the most relevant data sets in response to a search query from a user. Only in this manner can the information stored in the database be rendered optimally usable for the user. This applies particularly to catalog functions in which the data sets correspond, for example, to individual products, for example in a web shop. The user expects that precisely those products which are relevant to him will be displayed to him in response to a search query. Conversely, it is in the vital interest of a web shop owner to present the most relevant products to the user. Other examples are, for instance, library catalogs, scientific databases, reference material or files.
Nevertheless, in common search methods, the problem of irrelevant data sets being found arises, for example in the case of ambiguous search terms or because artefacts arising from the search method used occur. This results in the actually relevant hits being displayed only far down a list organized according to the determined relevance, for example, and the user not finding these hits or finding them only with difficulty. In the case of a web shop for example, such an inefficient search function leads to frustration on the part of the user and to losses in turnover for the owner.